Marking apparatus including a vertical column serving for guiding and holding a marking arm

ABSTRACT

A marking apparatus of the type in which an apparatus arm is mounted on a vertical column having the bottom end thereof rotatably mounted in a base plate and lockable by a locking means at selected rotary positions with respect to the base plate. An arcuate guide rail is spaced outwardly from the bottom of the column and a radial arm extends outwardly from the column to fit over the guide rail. An oblique strut extends from the upper portion of the column to the radial arm which is selectively clamped to the guide rail.

United States Patent Freund June 3, 1975 MARKING APPARATUS INCLUDING A [56] References Cited VERTICAL COLUMN SERVING FOR UNITED STATES PATENTS GUIDING AND HOLDING A MARKING 2,438,813 3/1948 Lundeen 33/19 B ARM 3,633,949 1/1972 Pfluger 74/568 R x Inventor: Franz Freund, Aschaffenburg,

Germany Assignee: Mora Fabrik fuer Mebgeraete H.

Freund, Germany Filed: Jan. 28, 1974 Appl. No.: 436,907

Foreign Application Priority Data Jan. 30, I973 Germany 2304401 US. Cl. 74/813 L; 33/19 B; 74/568 R Int. Cl B23b 29/00 Field of Search 74/813 L, 813 R, 568 R;

Primary ExaminerSamuel Scott Assistant ExaminerF. D. Shoemaker Attorney, Agent, or Firm-Griffin, Branigan and Butler [5 7] ABSTRACT A marking apparatus of the type in which an apparatus arm is mounted on a vertical column having the bottom end thereof rotatably mounted in a base plate and lockable by a locking means at selected rotary positions with respect to the base plate. An arcuate guide rail is spaced outwardly from the bottom of the column and a radial arm extends outwardly from the column to fit over the guide rail. An oblique strut extends from the upper portion of the column to the radial arm which is selectively clamped to the guide rail.

20 Claims, 3 Drawing Figures PATH-Emlyn 1975 38861312 SHEET 1 wan-mm m5 3886B 1 2 SHEET 2 FIG. 3

1 MARKING APPARATUS INCLUDING A VERTICAL COLUMN SERVING FOR GUIDING AND HOLDING A MARKING ARM This invention relates to a marking apparatus of the type in which a marking arm is mounted on a vertical column which is rotatably connected to a base plate. but lockable thereto at predetermined rotational positions relative to the base plate.

German Pat. No. 1,145,363 illustrates prior such which are adapted to mount a marking tool on a vertically adjustable column having a large diameter threaded portion for engaging an internally threaded base plate so that relative rotation therebetween causes vertical adjustment of the column. In such structures. however, an axial guide hinders rotation of the marking arm and the vertical column. Hence. such devices are unsuited for operations wherein it is desired that the marking or tracing tools scribe a circular are about the axis of the vertical column, for example.

Other marking devices have been constructed wherein a locking device retains a vertical column at predetermined rotational positions relative to a base plate, but these devices have not been entirely satisfactory either.

In other devices, a slide bearing might be located at the foot of a column; and my German Pat. No. 2,204,024 illustrates still another prior device. Therein, as also illustrated in FIG. 1 herein, a shoulder on the bottom of the column abutts an axial roller bearing located in a bearing housing of the base plate. Therebelow, a radial roller bearing is fitted around the buttend of the column shaft; and an angular bearing is located around the shaft below the radial bearing. In this regard. the inner race of the angular bearing is clamped against axial motion with respect to the shaft so that the axial bearing prevents axial motion of the shaft; the radial bearing prevents radial motion thereof; and the angular bearing prevents the lower portion of the shaft from moving at angles therebetween.

The above described structure of my German Pat. No. 2,204,024 substantially eliminates axial and angular backlash or play" at the butt end of the column shaft, but its advantages are diminished when the vertical column undergoes bending. Hence, it is an object of the present invention to provide a rotatable vertical column for a marking apparatus wherein the benefits of such play-free advantages thereof are not effectively lost when bending moments are applied to the vertical column.

Now the object of the present invention is to solve the problem of constructing a marking apparatus'ineluding a rotatable vertical column so that the accuracy achieved for the foot of the column by the freedom of backlash of the bearing construction does not get lost by a bending of the rotatable vertical column of the apparatus.

SUMMARY OF A PREFERRED EMBODIMENT OF THE INVENTION In accordance with principles of the invention. a radial arm is secured to the column near its base and extends outwardly therefrom to a circular-shaped guide rail which surrounds the column. A strut is secured to the upper end of the column and extends obliquely to the rail-end of the radial arm. A clamping means is then provided for selectively clamping the radial arm to the guide rail which is preferrably concentrically located about the column. In this manner, if the column tends to bend. the compressive and tensile forces thereof are transmitted to the strut which, in turn, transmits them to the radial arm and guide rail to prevent the column from actually being bent.

The guide rail is preferably coaxial relative to the column of said apparatus, and said radial arm engages about said guide rail in a manner such that both pressure forces and tensile forces of the strut can be transmitted to the guide rail and picked up by this guide rail.

BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and other objects, features, and advantages of the invention will be apparatent from the more particular description of preferred embodiments thereof as illustrated in the accompanying drawings wherein:

FIG. 1 is a vertical partially sectional view of the lower portion of a marking apparatus of the invention including a vertical column supported by a strut;

FIG. 2 is a partial plan view of a sector-shaped section of the marking apparatus according to FIG. 1; and

FIG. 3 is a vertical partially sectional view of another embodiment of a marking apparatus similar to FIG; 1.

The marking apparatus according to FIG. 1 has a vertieal column 2 which serves for guiding and holding an apparatus arm. The butt end 3 of the column 2 has multiple offsets thereon to accommodate the axial, radial, and angular bearings discussed above. Similarly, the base plate 4 has corresponding offsets and shoulders to accommodate the bearings as illustrated in the drawings. In this respect, a flange 5 near the base of the column 3 is continuously connected to a central extension 23 of the base plate 4 as illustrated.

The flange 5 has a laterally projecting boss 24, to which is clamped a mounting flange 25 for a radial arm 26 having a recess 27 which is adapted to fit over a ring-shaped guide rail 28 as shown. The guide rail 28 is concentric with the column 2 as is evident, for example, from FIG. 2, and is fixedly screwed to a ringshaped mounting extension 30 of the base plate 4 by means of screws 29.

A clamping foot 31 is adapted to be clamped against the underside of the guide rail 28 by means of a thumb screw 32 in a manner such that the radial arm 26 is securely fixed to the guide rail 28.

The radial arm 26 constitutes a fastening location for the lower end of a strut 33 which, with its upper end, is anchored by a threaded extension and a nut 34 to a mounting arm 35 extending away from the upper end of the column 2. Hence, upon release of the thumb screw 32, the column 2, the lower anchoring point. and the strut 33 are adapted to rotate together. In this respect, it is to be noted that the clamping means formed by the clamping foot 31 and thumb screw 32 also serves to fix the rotary position of the column 2 so that they eliminate the requirement for special locking devices at the lower end 3 of the shaft 2.

The embodiment shown in FIG. 3 differs from that according to FIGS. I and 2 in that, instead of the clamping means formed of the clamping foot 31 and the thumb screw 32. there are two wedge pieces 36 and 37 located in a recess of the radial arm 26. When the wedge piece 37 is pulled upwardly by a thumb screw 38, the wedge piece 36 is pressed against the guide rail 3 28 to produce a firm clamp between the guide rail 28 and the radial arm 26.

A member 39 is affixed to the radial arm 26 by screws not shown and engages the underside of guide rail 28 so that the strut 33 can also transmit tensile forces for supporting the column 2. Hence, the top of column 2 is prevented from being bent and the benefits of the structures bearings are retained.

In addition to the foregoing examples of clamping means for fixing the radial arm 26 to the guide rail 28. other embodiments of such clamping means will be apparent to a man skilled in the art.

What is claimed is:

l. A marking apparatus of the type in which an apparatus arm is mounted on a vertical column having the bottom end thereof rotatably mounted in a base plate and lockable by a locking means at selected rotary positions with respect to said base plate, said apparatus comprising:

a guide rail spaced outwardly from the bottom of said column;

a radial arm secured at one end to said column and extending outwardly therefrom to engage said guide rail; and

an oblique strut extending from an upper portion of said column to said radial arm.

2. The apparatus of claim 1 wherein said guide rail is arcuate and the arc thereof is coaxial with said column.

3. The apparatus of claim 1 including a clamping means for selectively clamping the engaging portion of said radial arm to said guide rail.

4. The apparatus of claim 3 wherein said clamping means includes afoot adjustably attached to said radial arm; and

means for clamping said'foot to the underside of said guide rail. 5. The apparatus of claim 3 wherein said clamping means includes a wedge means having at least one 'mcmber thereof adjustably attached to said radial arm;

and

means for moving said one member so thatsaid wedge means is clamped to said rail. 6. The apparatus of claim 3 wherein said locking means includes said clamping means.

7. The apparatus of claim 1 wherein said radial arm includes a groove and said guide rail is shaped to fit in guide rail. 10. The apparatus of claim 9 wherein said clamping means includes a wedge means having at least one member thereof adjustably attached to said radial arm;

and

means for moving said one member so that said wedge means is clamped to said rail.

ll. The apparatus of claim 7 wherein said locking means includes said clamping means.

12. The apparatus of claim 1 including additional means releaseably secured to said radial arm for engaging the underside of said guide rail to prevent upward motion of said radial arm and said oblique strut with respect to said guide rail.

13. The apparatus of claim 12 including a clamping means for selectively clamping the engaging portion of said radial arm to said guide rail.

14. The apparatus of claim 13 wherein said clamping means includes a foot adjustably attached to said radial arm; and

means for clamping said foot to the underside of said guide rail.

15. The apparatus of claim 13 wherein said clamping means includes a wedge means having at least one member thereof adjustably attached to said radial arm: and

means for moving said one member so that said wedge means is clamped to said rail.

16. The apparatus of claim 13 wherein said locking means includes said clamping means.

17. The apparatus of claim 1 wherein said guide rail is arcuate and coaxial with said column, said radial arm including a mating groove so that said guide rail fits into said groove;

a clamping means for selectively clamping the engaging portion of said radial arm to said guide rail; and additional means releaseably secured to said radial arm for engaging the underside of said guide rail to prevent upward motion of said radial arm and said oblique strut with respect to said guide rail.

18. The apparatus of claim 17 wherein said clamping means includes afoot adjustably attached to said radial arm; and

means for clamping said foot to the underside of said guide rail.

19. The apparatus of claim 17 wherein said clamping means includes a wedge means having at least one member thereof adjustably attached to said radial arm; and

means for moving said one member so that said wedge means is clamped to said rail.

20. The apparatus of claim 17 wherein said locking means includes said clamping means. 

1. A marking apparatus of the type in which an apparatus arm is mounted on a vertical column having the bottom end thereof rotatably mounted in a base plate and lockable by a locking means at selected rotary positions with respect to said base plate, said apparatus comprising: a guide rail spaced outwardly from the bottom of said column; a radial arm secured at one end to said column and extending outwardly therefrom to engage said guide rail; and an oblique strut extending from an upper portion of said column to said radial arm.
 1. A marking apparatus of the type in which an apparatus arm is mounted on a vertical column having the bottom end thereof rotatably mounted in a base plate and lockable by a locking means at selected rotary positions with respect to said base plate, said apparatus comprising: a guide rail spaced outwardly from the bottom of said column; a radial arm secured at one end to said column and extending outwardly therefrom to engage said guide rail; and an oblique strut extending from an upper portion of said column to said radial arm.
 2. The apparatus of claim 1 wherein said guide rail is arcuate and the arc thereof is coaxial with said column.
 3. The apparatus of claim 1 including a clamping means for selectively clamping the engaging portion of said radial arm to said guide rail.
 4. The apparatus of claim 3 wherein said clamping means includes a foot adjustably attached to said radial arm; and means for clamping said foot to the underside of said guide rail.
 5. The apparatus of claim 3 wherein said clamping means includes a wedge means having at least one member thereof adjustably attached to said radial arm; and means for moving said one member so that said wedge means is clamped to said rail.
 6. The apparatus of claim 3 wherein said locking means includes said clamping means.
 7. The apparatus of claim 1 wherein said radial arm includes a groove and said guide rail is shaped to fit in said groove.
 8. The apparatus of claim 7 including a clamping means for selectively clamping the engaging portion of said radial arm to said guide rail.
 9. The apparatus of claim 8 wherein said clamping means includes a foot adjustably attached to said radial arm; and means for clamping said foot to the underside of said guide rail.
 10. The apparatus of claim 9 wherein said clamping means includes a wedge means having at least one member thereof adjustably attached to said radial arm; and means for moving said one member so that said wedge means is clamped to said rail.
 11. The apparatus of claim 7 wherein said locking means includes said clamping means.
 12. The apparatus of claim 1 including additional means releaseably secured to said radial arm for engaging the underside of said guide rail to prevent upward motion of said radial arm and said oblique strut with respect to said guide rail.
 13. The apparatus of claim 12 including a clamping means for selectively clamping the engaging portion of said radial arm to said guide rail.
 14. The apparatus of claim 13 wherein said clamping means includes a foot adjustably attached to said radial arm; and means for clamping said foot to the underside of said guide rail.
 15. The apparatus of claim 13 wherein said clamping means includes a wedge means having at least one member thereof adjustably attached to said radial arm; and means for moving said one member so that said wedge means is clamped to said rail.
 16. The apparatus of claim 13 wherein said locking means includes said clamping means.
 17. The apparatus of claim 1 wherein said guide rail is arcuate and coaxial with said column, said radial arm including a mating groove so that said guide rail fits into said groove; a clamping means for selectively clamping the engaging portion of said radial arm to said guide rail; and additional means releaseably secured to said radial arm for engaging the underside of said guide rail to prevent upward motion of said radial arm and said oblique strut with respect to said guide rail.
 18. The apparatus of claim 17 wherein said clamping means includes a foot adjustably attached to said radial arm; and means for clamping said foot to the underside of said guide rail.
 19. The apparatus of claim 17 wherEin said clamping means includes a wedge means having at least one member thereof adjustably attached to said radial arm; and means for moving said one member so that said wedge means is clamped to said rail. 